On the Impossibility of Three-Move Blind Signature Schemes

The authors investigate the possibility to prove security of the well-known blind signature schemes by the researchers in the standard model, i.e., without random oracles. They subsume these schemes under a more general class of blind signature schemes and show that finding security proofs for these schemes via black-box reductions in the standard model is hard. Technically, their result deploys meta-reduction techniques showing that black-box reductions for such schemes could be turned into efficient solvers for hard non-interactive cryptographic problems like RSA or discrete-log.